An official report says that schools and colleges should encourage teenagers to continue taking maths in the sixth-form amid concerns too many young people are unfit for the demands of university or the workplace.

Every teenager in England should be given maths lessons even if they fail to sit a full A-level in the subject, it is claimed.

It coincides with a decision to increase the education leaving age from 16 at the moment to 17 in 2013 and 18 in 2015. All young people will be forced to remain in school, college or some form of on-the-job training.

The recommendation – in a document published by the Department for Education – comes amid growing concerns over standards of advanced numeracy skills.

On Friday, a study by the Sutton Trust charity showed that teenagers in England were less likely to score top results in international maths tests than in almost any other developed nation.

The country was ranked 26th out of 34 in terms of the proportion of pupils reaching high standards in the subject, with pupils being around four times less likely to achieve good scores than those in Switzerland and South Korea.

Pupils are also much less likely to study A-level style maths than almost anywhere else in the developed world, it emerged.

Elizabeth Truss, the Conservative MP for South West Norfolk, who has campaigned for improved standards of maths education, said: “It is shameful that England has the lowest proportion of students taking maths post-16 in the developed world.

“This is hampering social mobility and competitiveness. Studying maths provides higher economic returns than any other subject, with maths A-level resulting in a 10 per cent earnings premium. There is a shortage of qualified students for university places and industry.”

A policy paper released by the DfE earlier this week set out a series of reforms designed to boost standards of qualifications sat by pupils between the age of 16 and 19.

It said that all pupils who fail to gain at least a C grade in GCSE English and maths at 16 would be expected to carry on studying these subjects until they achieve a good mark.

But it said the Government was also committed to a “broader ambition” to get all pupils to carry on with maths until 18, regardless of standards achieved in GCSEs.

“Schools and colleges should encourage young people to continue with their study of maths once they have achieved a Level 2 [GCSE] qualification, in light of the value placed on mathematical ability by employers and higher education institutions,” said the report.

The conclusions came as maths teachers and academics prepared to call for a new suite of sixth-form courses to be developed to enable pupils to carry on studying the subject post-16 – giving them a recognised qualification for the extra study.

The Advisory Committee on Mathematics Education, which represents subject experts and teachers, said A-levels were seen as “inaccessible or inappropriate” to any student who failed to gain an A grade in the subject at 16.

In a report to be published next week, they will say: “Access to a well-recognised qualification is effectively denied to the 250,000-plus people who achieve a grade B or C at GCSE. These people have achieved a good grade by league table standard, but in mathematics they are effectively disenfranchised.

“Put simply, the vast majority of young people have no widely-recognised way of continuing to study mathematics after GCSE."

A DfE spokesman said: “All young people must be able to demonstrate their understanding of maths, whether they are going onto further study or into employment. A good qualification in maths is demanded by employers.

“That is why we have announced plans for all young people who fail to get a C or better in GCSE maths to study the subject up to 18, until they get a good qualification.”